<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<button>获取更多数据</button>
		<script type="text/javascript">
			var oBtn = document.getElementsByTagName('button')[0];
			oBtn.onclick = function() {
				this.innerHTML = '加载中....';

				// 加下划线告诉别人这是私有的变量
				var _self = this;
				window.setTimeout(function() {
					_self.innerHTML = '获取更多数据'; // this指向windown
				}, 2000);
			}
		</script>
	</body>
</html>
